Picture the the office toilets - your poopal is the guy/girl you can hear sitting in next toilet partition shitting like you. He/she can clearly hear that you are pooing, and you can hear them poo. Poopals very rarely meet in person after pooing, the last one usually waits till long after the first one has finished. Poopals are often unwanted as they ruin the moment of peace and quiet reflection you had going on until he/she arrived.
"Geesh was my poopal splashing when his turds hit the water"
by DenStarke May 25, 2007